import java.sql.*;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
//
//         查询
//        m1();
//
//         条件查询
//        m2();
//
//         增加
//       m3();
//
//        删除
//       m4();
//
//        修改
//        m5();
    }
    private static void m1(){
        // 1、加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接(url,name,password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "123456");
//            if (connection !=null)
//                System.out.println("连接成功");
            // 3、写sql
            String sql = "select * from sys_user";
            //4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);
            //5、有参数设置参数

            //6、执行sql
            ResultSet resultSet = preparedStatement.executeQuery();
            //7、遍历结果集
            while (resultSet.next()) {
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id + "--------" + name + "--------" + pass);
            }
            //8、关闭资源
            resultSet.close();
            preparedStatement.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            throw new RuntimeException();
        } catch (SQLException ex) {
            throw new RuntimeException(ex);
        }
    }
    private static void m2(){
        try {
            Scanner sc=new Scanner(System.in);
            System.out.println("输入要查询的姓名：");
            String word=sc.next();
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接(url,name,password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "123456");
            // 3、写sql
            String sql = "select * from sys_user where name like ?";
            //4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);
            //5、有参数设置参数
            preparedStatement.setObject(1,"%"+word+"%");
            //6、执行sql
            ResultSet resultSet = preparedStatement.executeQuery();
            //7、遍历结果集
            while (resultSet.next()) {
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id + "--------" + name + "--------" + pass);
            }
            //8、关闭资源
            resultSet.close();
            preparedStatement.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            throw new RuntimeException();
        } catch (SQLException ex) {
            throw new RuntimeException(ex);
        }

    }
    private static void m3(){
        try {
            Scanner sc=new Scanner(System.in);
            System.out.println("输入要新增的姓名：");
            String name=sc.next();
            System.out.println("输入要新增的密码：");
            String pass=sc.next();
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接(url,name,password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "123456");
            // 3、写sql
            String sql = "insert into sys_user(id,name,pass) values (3,?,?)";
            //4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);
            //5、有参数设置参数
            preparedStatement.setObject(1,name);
            preparedStatement.setObject(2,pass);
            //6、执行sql
           int result=preparedStatement.executeUpdate();
            //7、结果判断
           if (result>0)
               System.out.println("添加成功");
            //8、关闭资源
            preparedStatement.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            throw new RuntimeException();
        } catch (SQLException ex) {
            throw new RuntimeException(ex);
        }
    }
    private static void m4(){
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接(url,name,password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "123456");
            // 3、写sql
            String sql = "delete from sys_user where id=?";
            //4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);
            //5、有参数设置参数
            preparedStatement.setObject(1,2);
            //6、执行sql
            int result=preparedStatement.executeUpdate();
            //7、结果判断
            if (result>0)
                System.out.println("删除成功");
            //8、关闭资源
            preparedStatement.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            throw new RuntimeException();
        } catch (SQLException ex) {
            throw new RuntimeException(ex);
        }
    }
    private static void m5(){
        try {
            Scanner input = new Scanner(System.in);
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接(url,name,password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "123456");
            // 3、写sql
            System.out.println("请输入要修改用户的id:");
            int id = input.nextInt();
            System.out.println("请输入修改后的用户的name");
            String name = input.next();
            System.out.println("请输入修改后的用户的pass");
            String pass = input.next();
            String sql = "UPDATE sys_user SET name = ?,pass=?  WHERE id = "+id;
            //4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);
            //5、有参数设置参数
            preparedStatement.setObject(1,name);
            preparedStatement.setObject(2,pass);
            //6、执行sql
            int result=preparedStatement.executeUpdate();
            //7、结果判断
            if (result>0)
                System.out.println("修改成功！");
            //8、关闭资源
            preparedStatement.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            throw new RuntimeException();
        } catch (SQLException ex) {
            throw new RuntimeException(ex);
        }
    }

}